1,721,021 research outputs found
Resilient power in hospitals: The S. Giovanni addolorata general hospital case study
No full textThe hospital's electric power system is typically complex, with a round the clock, 365 days per year required mission. Although normally the supply of electricity is taken for granted, natural disasters and terrorist attacks remind us how dependent we are on electricity and how fragile the system can be. In order to cover such a topic, resilience has been defined as the ability of a system to reduce the chances of a shock, to absorb if it occurs and to recover quickly after a shock. The paper deals with the resilience of hospitals' electric power system. In particular, the way how actual hospitals are able to face power loss following a disaster and whether the typical power system's layout is adequately resilient is discussed. Finally, the case study of an 800-beds acute care general hospital in Rome that has started its path toward power resilience enhancement is illustrated. In particular, a new 190 kW PV system has been recently implemented at the hospital, thanks to a European financing, and some low-cost-measures, as adoptable on the actual power system's layout with the aim of cost-effectively increasing its resilience, have been identified
Surveying PQ Aspects in Italian Industrial Customers
No full textThe paper has the objective to identify levels of Power Quality (PQ) at industrial customers in the various areas of Italian electric system. To this aim, the results of two different questionnaire based surveys performed so far in different Italian Districts have been analyzed in comparison in order to derive general rules and guidelines concerning PQ aspects. The surveys have involved, as a whole, a sample of about 200 industrial customers located in central and northern areas of the Country. The surveys have concerned even some aspects relevant to costs of PQ problems. The main results as obtained from either the surveys are reported and discussed
Characterization of Fluctuating Harmonics from Single-Phase Power Electronics Based Equipment
No full textselezionato per pubblicazione su Rivista internazionale COMPE
Reliability optimization of PLC-integrated high-quality power supply protection systems
No full textThe authors deal with the analysis of some possibilities related to the adoption of the programmable logic controller (PLC) in a protection system for a medium-voltage electrical installation. A reliability evaluation of the entire protection system as obtained with PLC adoption is performed in order to point out every possible advantage of this promising technical solution. A correct reliability evaluation of PLC integrated solutions must analyze the entire system behavior if there is a PLC failure to indicate improved reliability indices of the whole system. On the basis of numerical evaluations, some design criteria on protection system logic are proposed, which allows achievement of a noticeable improvement of these indices, by means of an appropriate choice of tripping logic between positive and negativ
An Easy Maintenance Power Control For Stand Alone Pv Systems With Grid Interconnection Capabilities
No full textA low-cost IoT solution for power availability improvement in hospitals
Full text linkPower is a crucial element in hospitals whether it's within the intensive care units, surgical bays, or medical scanning rooms. Without reliable power, patients’ lives are at risk. The power availability improvement is therefore a crucial point in healthcare. A supervising system superimposed to the main components of the power system as able to promptly signal anomalies or malfunctioning or outages can be very useful for this task. To this aim, an Internet of Things (IoT) based solution has been implemented that allows equip at low cost the various electrical components in the distribution MV/LV substations of the hospital’s power system so as to be connected to a central supervising system. The solution implements a platform based on Rapsberry pi 3
Time-varying harmonics of single-phase non-linear appliances
No full textThe paper deals with the time-variant behavior of harmonic currents produced by single-phase non-linear (NL) appliances. The harmonic currents have been monitored in a broad field measurement activity that has concerned several samples of the more widespread appliance types in a power demand range up to hundreds of Watts. For the measurement activity a custom system allowing the continuous harmonic monitoring of voltage and current signals has been used. The results obtained show that for almost all the investigated appliances a not negligible variation of harmonic currents with time can be found. The possible causes of the observed behavior are discussed in detail. Finally, the utility of specific statistical and graphical tools for approaching the problem is discussed
Cellular phone battery charges impact on voltage quality
No full textSeveral types of widespread battery chargers have been investigated in laboratory. A continuous harmonic current monitoring activity has been performed with a custom system in order to capture time-varying characteristics of harmonic absorption due to battery chargers typical duty-cycle. Finally, by using a novel method based upon laboratory tests, some curves have been proposed which allow predict voltage distortion impact at the point-of-common coupling (PCC) in presence of attenuation phenomena
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